Threat Description

Backdoor: W32/SdBot.CNG


Category: Malware
Type: Backdoor
Platform: W32
Aliases: Virus.Win32.Virut, Backdoor.Generic.178032, Worm:Win32/Neeris.AN (Microsoft) , W32/Virut.gen.A (McAfee)


A remote administration utility which bypasses normal security mechanisms to secretly control a program, computer or network.


Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.

More scanning & removal options

More information on scanning or removal options is available in the documentation for your F-Secure security product on the Downloads section of our Home - Global site.

You may also refer to the Knowledge Base on the F-Secure Community site for more information.

Contact Support

For further assistance, F-Secure customers can request support online via the Request support or the Chat forms on our Home - Global site.

Technical Details

Backdoor:W32/SdBot.CNG is a backdoor program that can be controlled by an attacker through an Internet Relay Chat (IRC) channel. The program itself is usually sized around 28 to 55 kB.


SdBot.CNG is propagated through multiple vectors:

  • Removable media such as USB thumb drives
  • Instant Messaging (IM) networks (e.g., AIM, MSN, ICQ and Triton)
  • Network shares
  • Peer-to-Peer (P2P) networks (e.g., Edonkey2000, Morpheus, KAZAA, LimeWire, BearShare and Grokster) via the application's shared folders

During installation, SdBot.CNG creates a copy of itself in one of these folders:

  • %windir%system\VMwareservice.exe
  • %windir%system32\csrsc.exe

While active, the backdoor has the following functionalities:

  • Perform SYN Floods
  • Perform Distributed Denial of Service (DDoS) attacks
  • View MSN, AIM and Triton threads
  • Propagate via AIM, MSN and Triton
  • Download files
  • Update itself
  • Steal passwords from Protected Storage
  • View and create processes
  • Visit user defined websites
  • Perform shell executions

SdBot.CNG is also able to detect applications or services such as VMware, Nepenthes, sandboxes and honeypots.


The backdoor program creates on of the following Registry keys in order to automatically execute the copy of itself saved in the Windows directory:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VMwareService = "VMwareService.exe"
  • HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\VMwareService = "VMwareService.exe"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinSpoolSvc = "csrsc.exe"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentSet001\Services\WinSpoolSvc = "csrsc.exe"

It also creates the following Autorun.inf to facilitate its propagation on removal media such as USB thumb drives:

  • [autorun] open = RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213\autorunme.exe icon=%SystemRoot%\system32\SHELL32.dll,4 action=Open folder to view files
  • [autorun] open = RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213\autorunme.exe icon=%SystemRoot%\system32\SHELL32.dll,4 action=Open folder to view files shell\open=Open shell\open\command=RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213\autorunme.exe shell\open\default=1


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